Street canyon flow regimes are classified using the time-averaged mean flow. The present paper discusses recent work on the dynamics of street canyon flows (important for pollutant transport) and the interaction with the shear layer and atmospheric boundary layer above, with a view to classifying the different regimes in terms of the unsteady characteristics of the flow for different types of c...

Comparative study of measured and modelled number concentrations of 1 nanoparticles in an urban street canyon 2 Prashant Kumar , Andrew Garmory, Matthias Ketzel, Ruwim Berkowicz, and Rex Britter 3 Department of Engineering, University of Cambridge, CB2 1PZ Cambridge, United Kingdom 4 School of Engineering, University of Surrey, Guildford GU2 7XH, United Kingdom 5 Department of Atmospheric Envir...

A successful urban planning and design solution ought to present a comfortable setting for its pedestrians inside urban canyons, because it is fundamental to encourage a good quality urban life and promote health and wellbeing of humans. Recent findings have demonstrated that microclimate inside urban canyons has substantial influence upon the outdoor thermal comfort at the street level .This s...

Four geometrical configurations of a real street canyon in Barreiro city (Portugal) are considered to study their influence on the dispersion of PM10. These configurations include actual architectural layout of the street (Option 1), and three virtual cases (Options 1-3). Option 2 includes the modification of real geometry by including 4 m gaps between the buildings situated on the southern par...

Pseudo–simultaneous measurements for vertical variation of coarse, fine and ultra fine particles in an urban street canyon. Atmospheric Environment 42, 4304–4319. Abstract 1 The vertical variation of particle number distributions and concentrations in a street 2 canyon is the result of the competing influences of meteorology, traffic and transformation 3 processes overall and for various partic...

CFD modeling using RANS and LES of pollutant dispersion in a three-dimensional street canyon is investigated by comparison with measurements. The purpose of this study is to confirm the accuracy of LES in modeling plume dispersion in a simple street canyon model and to clarify the mechanism of the discrepancy in relation to RANS computation. Simple LES modeling is shown by comparison with wind ...

In recent past, significant efforts have been made to improve the scientific understanding of exhaust dispersion phenomenon in urban street canyons/intersection. The amount of turbulence generated by natural winds within the street canyon might be smaller than that of traffic induced turbulence. Therefore, the influence of traffic-induced turbulence on exhaust dispersion has to be quantified. I...

Mean and turbulent flow characteristics together with particle concentrations were measured in a busy urban street canyon in Essen, Germany, at five (flow characteristics) and three heights (particles) above ground, respectively. Particle mass and number concentrations were sampled in the size range 0.3oDpo10 mm. The flow characteristics within the canyon were significantly influenced by canyon...

ABSTRACT: Bi-molecular reactions can affect the transport of air pollutants in urban street canyons. In numerical simulations, we need to evaluate the correlation between the concentrations of the reactants to know the reaction rate. In this paper, we examine the effects of the subgrid scale (SGS) on the reaction rate in large-eddy simulations (LESs). LESs coupled with an SGS variance model are...

Sound propagation between a courtyard and an adjacent street canyon, as influenced by a wide range of meteorological conditions, was investigated by means of a real-life experiment in a dense urban setting. During several months, test signals were emitted on a regular base by an outdoor loudspeaker in the courtyard and recorded by wall-mounted microphones in the courtyard and the street canyon....